William d



W. D. LUDLOW.

Preserve Can.

Patented June 28, 1859.

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PATENT OFFICE.

WILLIAM D. LUDLOVV, OF NE\V YORK, N. Y.

PRESERVE-CAN.

Specification forming part of Letters Patent No.

24,566, dated June 28, 1859; Reissued April 19,

T 0 all whom it may concern:

Be it known that I, WILLIAM D. LUDLow, of the city, county, and State ofNew York, have invented a new and useful Improvement in SealingProvision Cans; and I hereby declare the following to be a full andexact description of the same, reference being had to the accompanyingdrawings, making part of this specification.

The said improvement consists in a peculiar arrangement and combinationof the lugs and keys by which the cover is held down.

In the accompanying drawings, Figure l is an axial section and Fig. 2 atop view of a can embodying my improvements.

A is the can formed with a depression or concavity (a) in its top whichreceives an india rubber gasket B.

C is the cover having sufficient external convexity for rigidity andprovided with a vertical flange atits periphery adapted to sink into thegasket B so as to form an air tight joint.

D, is a key or cross bar pivoted in the center to the cover C, andformed with oblique ends adapted to engage beneath oblique lugs E, E,upon the can.

F is a small disk of metal placed beneath the key D, concentrically withits pivot so as to distribute the pressure equally throughout thecircumference of the cover and prevent contact between the key and covernear the periphery.

To close the can the gasket and cover are placed in the position shownand the key D, rotated so as to pass its depressed corners 1, l, beneaththe lugs E, E, until the wedge like action compresses the cover upon thegasket with sufiicient force.

The lugs E, are soldered upon the inner face of the concavity a in orderthat the side of the said concavity may form a back or brace to preventthe rupture of the solder by the forcing of the key beneath the lugs.

The key D, has sufficient elasticity to permit the escape of steam inthe event of undue pressure occurring within the can, which is a wellknown and prolific source of imperfection in the joints of provisioncans. Upon the cooling of the contents the external pressure compressesthe cover more tightly upon its seat and effectually prevents theingress of air. The rapidity with which an air tight joint is formed bythis arrangement and the facility for retracting the key withoutremoving the cover afford means to test a can previous to using; in thefollowing manner. A piece of lighted paper being placed within the canand the cover quickly closed down in the manner before described, a.partial vacuum is formed in the can and if on retraction of the key itis found that the cover remains tightly closed by atmospheric pressurethe can is proved to be tight in all its joints. By this means the loss(amounting to many hundreds of dollars annually) which occurs fromputting up edibles in cans having unseen imperfections in their jointsmay be entirely avoided.

It is not essential to this invention that the central bearing F, shouldbe constructed in a separate piece as it may evidently constitute aprotuberance upon the key or the cover or both, its ofiice being toprevent an unequal pressure in any part of the periphery of the cover.Neither is it absolutely essential that the key ends and the lugs shouldboth be beveled. The same result can be obtained in an inferior mannerby the combination of straight lugs with a beveled key or vice-versa.

I claim as new and of my invention herein The described combination ofthe key D with lugs E attached in the manner shown to the sides of acavity (a), in the top of the can in order to prevent the disruption ofthe said lugs during the act of closing the can and avoid projectionsabove or beyond its periphery.

In testimony of which invention, I hereunto set my hand.

lV. D. LUDLOV. itnesses JOSEPH RICHTER,

C. S. SEWELL.

